Project Summary/Abstract Opioid use disorders, co-occurring with either depression or PTSD, are prevalent, burdensome, and too often left untreated. In 2015-16, there were over two million adults with a current OUD; 62% had a co-occurring mental illness and 24% had a co-occurring serious mental illness. However, despite the effectiveness of treatment, many individuals never receive treatment; and, when treatment is provided, quality is low. This is a critical treatment and quality gap in a vulnerable and stigmatized population. Collaborative care (CC) aims to address these gaps, and ground-breaking studies conducted by our team have shown that CC improves access, quality and outcomes in primary care patients with common mental health conditions, including addiction. However, CC has never been tested with co-occurring disorders (COD), despite research by our team suggesting it may be effective. CC consists of a team of providers that includes a care manager (CM), a primary care provider (PCP) and a behavioral health consultant (BHC), who provide evidence- and measurement-based care to a panel of patients using a clinical registry. In our CC model for COD (CC-COD), the CC team also includes a behavioral health psychotherapist (BHP); the evidence-based treatments supported include medications for OUD (MOUD), pharmacotherapy for depression and PTSD, motivational interviewing (MI), problem solving therapy (PST) and Seeking Safety (SS). We build upon our prior research by emphasizing patient engagement and using a collaborative planning and development process to adapt the intervention for a setting that is resource-poor with few medical and behavioral health providers, and a highly stigmatized patient population with multiple interacting complex disorders. We propose a multi-site, randomized pragmatic trial in 11 rural and urban primary care clinics located in Health Professional Shortage Areas (HPSA) of New Mexico to adapt, harmonize and then test whether CC-COD improves access, quality and outcomes for primary care patients with co-morbid OUD and depression and/or PTSD. New Mexico has one of the highest opioid overdose death rates, and the CDC projects it will have the highest rates of death from drugs, alcohol and suicide in the nation by 2025. A primarily rural state, it is majority Hispanic. We will collaborate with the University of New Mexico Health Sciences Center, First Choice Health Care system, UNM?s North Valley Health Center, and Hidalgo Medical Services to conduct the study. We will randomize 1,000 patients with co-occurring OUD and and/or depression/PTSD to receive either CC- COD or enhanced usual care (EUC). Our primary outcomes are rates of MOUD initiation (access), quality of care for OUD, depression and PTSD (quality), self-reported physical and MH and wellbeing, and abstinence from opioids (outcomes). We will also examine mediators and moderators of treatment quality and outcomes, and assess contextual factors affecting implementation and sustainability.